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Chapter 13 Databases and Information Management

Chapter 13 Databases and Information Management. How are data and information related?. Computers process data into information Data is raw facts; information is data that is organized and meaningful. Data and Information. information. data. Next. p. 13.2 Fig. 13-1.

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Chapter 13 Databases and Information Management

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  1. Chapter 13Databases and Information Management

  2. How are data and information related? Computers process data into information Data is raw facts; information is data that is organized and meaningful Data and Information information data Next p. 13.2 Fig. 13-1

  3. What is a database? Collection of data organized so you canaccess, retrieve, and use it Database software allows you to Create database Add, change, and delete data Sort and query database Database software also is called database management system (DBMS) Data and Information Next p. 13.2

  4. What is data integrity? Degree to which data is correct When database contains errors, it loses integrity Data and Information Garbage in, garbage out (GIGO) Cannot create correct information from incorrect data Next p. 13.3

  5. What is a field? Combination of one or more characters Smallest unit of data user accesses Field name uniquely identifies each field The Hierarchy of Data fields Next p. 13.4 Fig. 13-3

  6. What are characteristics of a field? Data type Field size The Hierarchy of Data Text – letters, numbers, or special characters Numeric – numbers only Currency – dollar and cent amounts or numbers containing decimal values Date – month, day, year, and sometimes time information data types Memo – lengthy text entries Yes/No – only the values Yes or No Hyperlink – Web address that links to a document or a Web page Object – picture, audio, video, or a document created in other applications such as word processing or spreadsheet Next p. 13.5

  7. What is a record? Group of related fields The Hierarchy of Data field names maximum characters in Rating field records key fieldUniquely identifies each record in file Also calledprimary key Next p. 13.5 Fig. 13-2

  8. What is a data file? Collection of related records stored on disk Each record in file contains same fields Each field contains different data Also called a file Database usually composed of group of related data files The Hierarchy of Data fields Sample Customer File Next records p. 13.5 Fig. 13-3

  9. What is file maintenance? Procedure that keeps data current Maintaining Data Adding records Changing records Deleting records Next p. 13.6

  10. What is validation? Validity check analyzes entered data to help ensure it is correct Maintaining Data Next Click to view Web Link then click Validity Checks p. 13.9 Fig. 13-7

  11. What is a completeness check? Error message displays stating which required fields are blank Maintaining Data required information Next p. 13.10 Fig. 13-8

  12. Number(s) or character(s) appended to or inserted into primary key value Used to confirm accuracy of primary key value What is a check digit? Maintaining Data Initial primary key: 1367 Calculate total of digits: 1 + 3 + 6 + 7 = 17 Calculate total of digits again: 1 + 7 = 8 Check digit = 8 Resulting primary key: 13678 Next p. 13.10

  13. What is a file processing system? Each department or area within organization has own set of files Records in one file often do not relate to records in any other file File Processing Versus Databases Problem: same customer may have different name or address in each file Next p. 13.11 Fig. 13-9

  14. What is the database approach? Many programs and users can share data in database Secures data so only authorized users can access certain data items File Processing Versus Databases only one customer file in company database Next p. 13.12 Fig. 13-10

  15. What are the strengths of the database approach? File Processing Versus Databases Reduced data redundancy Improved data integrity Shared data Reduced development time Easier reporting Next p. 13.13

  16. How do a database application and a file processing application differ in the way they might store data? File Processing Versus Databases File processing example Database example Next p. 13.13 Fig. 13-11

  17. What is a database management system (DBMS)? Software that allows you to create, access, and manage a database Database Management Systems Next Click to viewanimation Click to view Web Link then click Database Management Systems p. 13.14 Fig. 13-12

  18. What is a data dictionary? Contains data about each file in database and each field within those files metadata Database Management Systems Next Click to view Web Link then click Data Dictionary p. 13.15 Fig. 13-13

  19. What is a query language? Simple, English-like statements that allow you to retrieve data to display, print, or store Database Management Systems query results Next p. 13.16 Fig. 13-14

  20. What is a query by example (QBE)? Program retrieves records that match criteria entered in form fields Database Management Systems query by example screen query results Next p. 13.17 Fig. 13-15

  21. What is a form? Window on screen that provides areas for entering or changing data in database E-form is similar, but used on Web Database Management Systems Next p. 13. Fig. 13-16

  22. What is a report generator? Generates report without user’s knowledge of programming Comes with a database Database Management Systems report Next p. 13. 19Fig. 13-18

  23. DBMS provides means to ensureonly authorized users can access data with specified privileges What is data security? Database Management Systems Access privileges Define activities that specific user or group of users can perform Read-only privileges User can retrieve data, but cannot change it Full-update privileges User can retrieve and change the data Next Click to view video p. 13.19

  24. What is a log? Listing of activities that change database contents For every change, DBMS places three items in log file Database Management Systems before image: a copy of the customer record prior to the change after image: a copy of the customer record after the change the actual change of data Next p. 13.20 Fig. 13-18

  25. What is a recovery utility? Uses log file and/or backups to restore database when it is damaged or destroyed Database Management Systems Rollforward DBMS uses log tore-enter changes made to database since last save or backup Also calledforward recovery Rollback DBMS uses log to undo any changes made to database during a certain period of time Also calledbackward recovery Next p. 13.20

  26. What is a data model? Every database and DBMS based on specific data model Composed of rules and standards Relational, Object-Oriented and Multidimensional Databases Relational Databases Object-oriented Databases Object-relational Databases Multidimensional Databases Next Click to viewanimation p. 13.21 Fig. 13-20

  27. What is a relational database? Stores data in tables that consist of rows and columns Each row has primary key Each column has a unique name Relational, Object-Oriented, and Multidimensional Databases Relational terminology Next Click to view Web Link then click Relational Databases p. 13.22 Fig. 13-21

  28. What is normalization? Process designed to ensure data within relations (tables) contains least amount of duplication Relational, Object-Oriented, and Multidimensional Databases row column table Next relationships p. 13.22 Fig. 13-22

  29. What is relational algebra? Uses variables and operations to build new relations Used to manipulate and retrieve data Relational, Object-Oriented, and Multidimensional Databases Projection operation Retrieves data from columns (fields) Selection operation Retrieves data from certain rows (records) Join operation Combines data from two or more tables Next p. 13.24

  30. What is an example of a projection operation? Extracts data from column (field) Relational, Object-Oriented, and Multidimensional Databases all rows and columns in Movie table projection operation results Next p. 13.24 Fig. 13-23

  31. What is an example of a selection operation? Extracts data from a row (record) Relational, Object-Oriented, and Multidimensional Databases all rows and columns in Movie table selection operation results Next p. 13.24 Fig. 13-23

  32. What is an example of a combined projection and selection operation? Extracts data from column (field) for certain rows (records) Relational, Object-Oriented, and Multidimensional Databases all rows and columns in Movie table projection and selection operation results Next p. 13.24 Fig. 13-23

  33. What is an example of a join operation? Combines data from two or more tables using a common column Relational, Object-Oriented, and Multidimensional Databases Rental Table Movie Table Rental Table and Movie Table joined on Movie ID Column Next p. 13.24 Fig. 13-24

  34. What is Structured Query Language (SQL)? Allows you to manage, update, and retrieve data Uses relational algebra Has special keywords and rules included in SQL statements Relational, Object-Oriented, and Multidimensional Databases projection operation join operation selection operation Next Click to view Web Link then click SQL p. 13.25 Fig. 13-25

  35. What is an object-oriented database (OODB)? Stores data in objects Advantages Can store more types of data Can access data faster Relational, Object-Oriented, and Multidimensional Databases Object Item that can contain both data and activities that read or process data Object query language (OQL) Manipulates and retrieves object-oriented and object-relational data Next Click to view Web Link then click Object-Oriented Databases p. 13.26

  36. What are examples of applications appropriate for an object-oriented database? Relational, Object-Oriented, and Multidimensional Databases Multimedia databases Store images, audio clips, and/or video clips Hypertext databases Contain text links to other documents Groupware databases Store documents such as schedules, calendars, manuals, memos, and reports Hypermedia databases Contain text, graphics, video, and sound Computer-aided design (CAD) databases Store data about engineering, architectural, and scientific designs Web databases Link to e-form on Web page Next p. 13.26

  37. What is a multidimensional database (MDDB)? Stores data in dimensions Relational, Object-Oriented, and Multidimensional Databases Advantage Can consolidate data much faster than relational database Next Click to view Web Link then click Multidimensional Databases p. 13.27

  38. What is the role of the database analyst and administrator? Database Administration Database analyst (DA) Focuses on meaning and usage of data Decides proper placement of fields, defines relationships among data, and identifies users’ access privileges Database administrator (DBA) Creates and maintains data dictionary, manages database security, monitors database performance, and checks backup and recovery procedures Next Click to view Web Link then click Database Administrator p. 13.30

  39. What is the role of the employee as a user? Employee should learn how to utilize data in database Take part in designing database that will help achieve company’s overall goals Database Administration Next p. 13.30

  40. What are guidelines for developing a database? Database Administration Next p. 13.30 Fig. 13-29

  41. What are the qualities of valuable information? Qualities of Valuable Information Accurate Cost-effective Organized Verifiable Useful Timely Accessible Next p. 13.30

  42. Qualities of Valuable Information Planning Planning Planning Planning Organizing Organizing Organizing Controlling Leading Leading Next How do managers use information? 1. objectives; strategies; tactics 2. money; people; management; structure 3. communication; instructions; motivation 4. performance; measurement; corrective action p. 13.32 Fig. 13-30

  43. What are the levels of users? Qualities of Valuable Information Focus on the company’s overall goals and objectives Applies specific programs and plans necessary to meet the stated objectives Applies specific programs and plans necessary to meet the stated objectives Involves day-to-day activities within the company Involves day-to-day activities within the company Involves day-to-day activities within the company Access information necessary to make decisions – a trend called empowering users Access information necessary to make decisions – a trend called empowering users Access information necessary to make decisions – a trend called empowering users Access information necessary to make decisions – a trend called empowering users Next p. 13.32 Fig. 13-31

  44. What is an information system? Set of hardware, software, data, people, and procedures that work together to produce information Types of Information Systems hardware people procedures Next software data p. 13.34 Fig. 13-32

  45. What are the five categories of information systems? Types of Information Systems Decision support systems Office information systems Management information systems Expert systems Transaction processing systems Next p. 13.34

  46. What is a management information system (MIS)? Generates accurate, timely, and organized information Managers and other users can Make decisions Solve problems Supervise activities Track progress Often integrated with transaction processing systems Types of Information Systems Next p. 13.36

  47. What is a detailed report? Lists one record per line Types of Information Systems Next p. 13.36 Fig. 13-34

  48. What is a summary report? Consolidates data, so you can review it quickly and easily Usually has totals, tables, or graphs Types of Information Systems Next p. 13.36 Fig. 13-34

  49. What is an exception report? Identifies data outside of normal condition Conditions, called exception criteria, define normal activity or status range Types of Information Systems Next p. 13.36 Fig. 13-34

  50. What is a decision support system (DSS)? Helps managers analyze data and make decisions One type of DSS is executive information system (EIS) Types of Information Systems Next Click to view Web Link then click Decision Support Systems p. 13.37 Fig. 13-35

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